TY  - JOUR
AU  - Xu, Zhenhua
AU  - Zeng, Linxiang
AU  - Hu, Jinlong
AU  - Wang, Zhenya
AU  - Zhang, Putao
AU  - Brabec, Christoph
AU  - Forberich, Karen
AU  - Mai, Yaohua
AU  - Guo, Fei
TI  - Reducing energy barrier of δ-to-α phase transition for printed formamidinium lead iodide photovoltaic devices
JO  - Nano energy
VL  - 91
SN  - 2211-2855
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2022-03321
SP  - 106658 -
PY  - 2022
AB  - Recent progress in perovskite photovoltaics has witnessed a growing interest in formamidinium lead iodide (FAPbI3), primarily due to its high efficiency potential and excellent stability. However, the high energy barrier of δ-to-α phase transition presents a major hurdle to fabricate phase-pure α-FAPbI3 layers. Here, we report a two-step phase transition process to deposit high-quality photovoltaic α-FAPbI3 films by printing method. This is realized by judicious selection of a Lewis base N-methyl-2-pyrrolidone (NMP) and its counter Lewis acid, which enables the regulation of intermediary phase to reduce the energy barrier. With fine tuning the phase transition pathway, phase-pure and stable α-FAPbI3 perovskite films are obtained, which yield solar devices with a champion efficiency of 21.35%. The printed mini-modules with active areas of 12.32 cm2 and 55.44 cm2 are also fabricated, giving efficiencies of 17.07% and 14.17%, respectively. This work provides new insights of α-FAPbI3 crystallization for constructing efficient and stable printed photovoltaic devices.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000717768500005
DO  - DOI:10.1016/j.nanoen.2021.106658
UR  - https://juser.fz-juelich.de/record/909653
ER  -